Measuring choroidal melanoma basal diameter: using ultrasound vs. a new wide–angle fundus camera

Abstract

Abstract: : Purpose: Largest basal diameter of choroidal melanoma is considered to be a significant clinical prognostic parameter, and is important in planning treatment of these tumors. The purpose of this study is to compare the measurements of the basal diameter by ultrasound to those obtained using a new wide–angle fundus camera. Methods: The basal diameter of 61 new and treated choroidal melanomas were measured by B–scan ultrasound and by a wide–angle fundus camera (Panoret–1000, Medibell Medical Vision Technologies, Haifa, Israel). The maximal diameter of each recognized elevated tumor was measured using ultrasound, while with the fundus camera the maximal diameter of the pigmented tumor was measured. The comparison was performed using summary statistics and paired t–test. Results: The mean long diameter was 10.66 ± 4.15 mm by Panoret–1000, and 9.48 ± 2.90 mm by ultrasound. The mean short diameter was 8.58 ± 3.25 mm by Panoret–1000 and 8.20 ± 2.50 mm by ultrasound. The Panoret–1000 measurements, on average, were 1.20 ± 3.55 mm longer for the long diameter and 0.40 ± 2.80 mm longer for the short diameter. These differences are both highly statistically significant (p < 0.0001). Conclusions: Assessment of basal diameter of uveal melanomas differs according to whether ultrasound or wide–angle fundus photography is used, favoring larger measurements with the fundus photography. We attribute this difference to the larger extent of the lesion's pigmentation than its elevation.

Keywords: melanoma • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • oncology